Department of Molecular Biology, University of Edinburgh, King's Buildings, Mayfield Road, Edinburgh EH9 3JR, UK.
EMBO J. 1984 Dec 20;3(13):3079-85. doi: 10.1002/j.1460-2075.1984.tb02262.x.
We have identified molecular lesions associated with six mutations, w and w, of the white gene of Drosophila melanogaster. These mutations arose in flies subject to I-R hybrid dysgenesis. Four of the mutations give rise to coloured eyes and are associated with insertions of 5.4-kb elements indistinguishable from the I factor controlling I-R dysgenesis. The insertion associated with w is at a site which, within the resolution of these experiments, is identical to that of two previously studied I factors. This appears to be a hot-spot for I factor insertion. We have compared the sites of these insertions with sequences complementary to white gene mRNA identified by Pirrotta and Bröckl. The hot-spot is in the fourth intron. The insertion carried by w is either within, or just beyond, the last exon. The insertion carried by w is near the junction of the first exon and first intron. The w mutation is a derivative of w. It contains an insertion of I factor DNA within, or immediately adjacent to, the F-like element associated with w, and results in restoration of some eye colour. This insertion is just upstream of the start of the white mRNA. Mutations w and w are deletions removing mRNA coding sequences. Both determine a bleached white phenotype.
我们已经确定了与果蝇白色基因 w 和 w 突变相关的分子病变。这些突变发生在经历 I-R 杂种不育的果蝇中。其中四个突变导致有色眼睛，并与控制 I-R 不育的 I 因子相同的 5.4kb 元件插入有关。与 w 相关的插入位于一个在这些实验分辨率内与之前研究的两个 I 因子相同的位置。这似乎是 I 因子插入的热点。我们比较了这些插入的位点与 Pirrotta 和 Bröckl 鉴定的与白色基因 mRNA 互补的序列。热点在第四个内含子中。w 携带的插入位于最后一个外显子内或其之外。w 携带的插入位于第一个外显子和第一个内含子的交界处附近。w 突变是 w 的衍生物。它在与 w 相关的 F 样元件内或紧邻其内部包含 I 因子 DNA 的插入，导致部分眼睛颜色的恢复。该插入位于白色 mRNA 起始点的上游。w 和 w 突变是删除 mRNA 编码序列的缺失突变。两者都决定了白化的表型。
